Process and apparatus for molding.



E. L. AIKEN.

PROCESS AND APPARATUS FOR MOLDING.

APPLlcnloN man 001.18, 1912.

1 ,1 90,072- A Patented July 4, 1916.

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UNITED STATES PATENT OFFICE.

EDWARD L. AIKEN, OF ORANGE, NEW JERSEY, ASSIGNOB, BY MESNE ASSIGNMENTS,

TO NEW JERSEY PATENT COMPANY, OF lWEST ORANGE, NEW JERSEY, A COBEOBIATION OF NEW JERSEY.

PROCESS AND APPARATUS FOB HOLDING.

Sp'ecilcation of Letters Patent.

Application led October 18, 1912. Serial No. 728,425. f

To all 'whom/et may concern:

Be it` known that I, EDWARD L. AIKEN,'a citizen of the United Statesanda resident of Orange, in the county of Essex and State of New Jersey,have invented a certain new and useful Improvement in Processes and-Apparatus for Molding, of which the following is a description.

My invention relates to processes and apparatus for molding, especiallyto those for use in connection with the pressing of disk sound recordsfrom a mass of plastic record material.

The principal objects of my invention are to vfacilitate the making of atrue and faithful sound record or other similar molded object and toprovide other improvements as will hereinafter appear.

- In the molding of objects by the pressing of a mass of plasticcomposition, such as a plastic sound record blank, against the face ormold surface of a mold, the accuracy of the impression in the moldedobject is frequently impaired by reason of the entrapping of air betweenthe composition and the mold when the former is pressed into the latter.This defect is especially marked when the object to be molded is a soundrecord; as the record surface of the mold or matrix is filled with smallelevations corre- /sponding in negative to the record undulations,between which elevations the air is entrapped to such an extent as torender the resultant record very imperfect. My invention contemplatesthe elimination of this objection by the exhaustion of the air frombetween the mold surface or surfaces and the plastic composition priorto the pressing operation, the vacuum thus obtained be ing maintaineduntil the composition has beerr pressed or formed into shape.

In order that my invention may be more clearl understood, attention ishereby directe to the accompanying drawing forming a part of thelspecification and in which- Figure 1 is a central vertical sectionalView showing one form of my improved apparatus prior to the applicationof pressure in the molding operation; and Fig. 2 is a similar Viewshowing the same apparatus after the application of pressure in themolding operation.

.In both of the views, like parts'. are desig-l nated by the samereference numerals.

The apparatus shownv comprises superposed flat mold plates 1 and 2,eaclrhaving a central depressed portion 3 vin which is secured a soundrecord matrix'4, each matrix as shown being provided with the usualreverse or negative of the sound record 'undulations. The matrices a'resecured in position in their respective mold plates by annular bushings5 threaded into the mold plates and provided with `headed portions 6bearing upon the matrices 4 and seated in recesses in the latter. Acentering pin 7 mounted in the lower bushing 5 and preferably securedtherein, as by friction, is adapted to be passed into the centralopening in the other bushing so as to hold the mold plates 1n alinement.The mold herein shown is what is termed a Hash mold, that is, a moldinywhich the excessmaterial" is forced out between the mold surfaces ofthe opposing mold plates, as shown in Fig. 2, when these plates arebrought together in pressing the plastic composition into shape. In themold shown, this excess material is forced intovthe hollow space betweenannular recesses 8 and 9 formed in the mold plates 1 and 2 respectivelya slight distance eyond the peripher of the matrices 4 andconcentrically with tlie latter, the portions of the opposing moldplates between the recesses 8 and 9 and the matrices 4 being so shapedas to leave the said recesses in communication with the space betweenthe matrices during the pressing operation. The mold plates arepreferably provided with inclined surfaces 10, 10 for forming theperiphery of the record during the pressing operation, these surfaces 10being soVv inclined that the finished record has its -larg est diametermidway between its flat or record bearing surfaces.

In order to render the mold air tight so as to permit of the productionof a vacuum therein, I provide a ring 11 of rubber or other suitableyielding material of such a size that the same is adapted to fit closelyagainst the peripheral portions of the mold platesv l and 2 to close'orseal the space between said plates, as clearly shown in Figs. 1 and 2.Disks 11 of rubber or other suitable yielding material may be placed inrecesses in the outer faces of the plates 1 and 2 and over the ends ofthe pin 7 and the outer ends of the bushings 5 to prevent the entranceof air around the end portions of the said pin to the space between themold plates. It will be seen that by reason of the yielding cha aeter ofthe ring 11, the mold plates may be moved toward each other from theposition shown in Fig. 1 a sufficient amount to permit the molding ofthe record without disturbing the vacuum between the said plates. Topermit the ready extraction 0f theair from the space between the moldpl'ates, I provide a hollow tubular connection 13 threaded into thelower mold plate 2 and communicating at its inner end with an annularslot 11 which in turn communi- Cates with the bottom of the recess 9.The outer end of the connection 13 is adapted to be connected with asuction pump or any other suitable air exhausting means whereby, afterthe mold plates and the ring 11 are in the positions indicated in thedrawing, air may be exhausted from the mold through the space betweenthe recesses 8 and 9 and the connection 13. A valve 15 is preferablyprovided in the connection 13 so as to permit the closing of the saidconnection to maintain the vacuum in the mold after the air has beenexhausted from the latter.

In using the apparatus described above, the matrices 4, 4 are firstsecured in position by the bushings 5, after which the plasticcomposition, such as the disk record blank or 'tablet 1Q shown, and theupper mold plate are. placed in position on the centering pin 7 with thematrices in contact with the faces of the blank or tablet. The ring 11is then placed in position around the mold plates to close or seal thespace between the same, as shown, after which the Yalve 15 is opened andthe air is withdrawn from the mold. Vhile theoretically best resultswould be obtained by the production of a complete vacuum, I find thatvery satisfactory results are obtained by a vacuum of 25 to 27 ofmercury.

The term vacuum7 in the appended claims is used in a general sense andis intended to cover any suitable partial vacuum.

A vacuum having thus been produced in the mold, the valve 15 is closedand the mold plates are forced toward each other in a suitable press.the composition of the blank 12 being first rendered sufficientlyplastic, as b v the application of heat. Of course, the valve 15 may, ifdesired, be kept open and the suction kept up during the pressingoperation. During the latter operation, the surplus composition will beforced into the recesses 8 and 9 and the record will be molded tosubstantially correctform, the record undulations being faithfullyreproduced in the finished record. All that remains to be done is t-opermit the molded record to become hardened, as by cooling in theatmosphere, after which air may be admitted between the mold plates, andthe ring 1], and the finished record removed.

IVhile I have described my invention in connection with the molding ofdisk sound records in which the record impression is formed in both ofthe faces of the record, it is evidently applicable as well to themolding of records in which the sound record impressions are formed inonly one face of the record and also to many other types of moldedarticles.

Many other changes may be made in the invention as specificallydescribed above and I do not, therefore, limit myself to the exactdetails shown.

VVhat I claim as new and desire to protect by Letters Patent of theUnited States is as follows:

1. The process of molding tablets which comprises placing moldablematerial be tween two mold plates, sealing the space between said platesto render the same air tight, withdrawing air from between said platesperipherally of said material and producing a vacuum in said space,rendering said material plastic, and pressing the same to shape betweensaid plates while maintaining said vacuum, substantially as set forth.

2. The process of molding disk records which comprises placing moldablematerial between two mold plates, one of which contains a mold surfacehaving a negative or reverse copy of record undulations therein, sealingthe space between said plates to render the same air tight, withdrawingair from between said mold surface and said material peripherally ofsaid material and producing a vacuum in said space, rendering saidmaterial plastic, and pressing the same to shape between said plateswhile maintaining said vacuum, substantially as set forth.

3. The process of molding disk records which comprises placing moldablematerial between two mold plates, each having a mold surface containinga negative or reverse copy, of record undulations, sealing the spacebetween said plates to render the same air tight, withdrawing air frombe tween said mold surfaces and said material peripherally of saidmaterial and producing a vacuum in said space, rendering said materialplastic, and pressing the same to shape between said plates whilemaintaining said vacuum, substantially as set forth.

1. The process of molding tablets which comprises placing moldablematerial between two mold plates. sealing the space between said plateswith a ring of yieldingr material to render the same air tight,withdrawing air from between said plates peripherally of said .materialand producing a vacuum in said space, rendering said maif 1,190,072 x5..The process of molding disk records which comprises placingmoldablematerial between two plates, one of which contains a mold"surfacehavinga negative or reverse copy of record undulations therein, sealingthe s acebetween said plates with a ring of yielding materialto renderthe jsame-v air tight, withdrawing airfrom between sa1d ,mold surfaceand said material peripherally of said material and producing a vacuum1n said space, rendering said material plastic, and pressing the same toshape between said plates while maintaining said vacuum, substantiallyas set forth. l

6. The process of molding disk records which comprises placing moldablematerial between two mold plates, each having a mold surface containinga negative or reverse copy of record undulations, ,sealing the spacebetween said plates with a ring of yielding material to renderA the sameair tight, withdrawing air from between said mold surfaces and saidmaterial peripherally of said material and producing a vacuum in saidspace, rendering said material plastic, and pressing the same to shapebetween said plates while maintaining said vacuum, substantially as setforth.

7 In apparatus of the class described, the combination of a plurality ofsuperposed mold plates, means'for sealing the space between the same t0prevent the entrance of air to said space, and means whereby air may beexhausted from said space, substantially as described.

8. In apparatus of the class described, the combination of a pluralityof superposed mold plates, a ring of yielding material surrounding saidplates for 'sealing the space between the same to prevent the entranceof air to said space, and means whereby air may be exhausted from saidspace, substantially as described.

9. In apparatus of the class described, the combination of a pluralityof superposed mold plates, means for sealing the space between the sameto prevent the entrance of air to said space, and a hollow connectioncommunicating with said space whereby air may be exhausted from thelatter, substantially as described.

10. In apparatus of the class described, the combination of a pluralityof superposed mold plates, a ring of yielding material surrounding saidplates for sealing the space between the same to prevent the entrance ofair to said space, and a hollow connection communicating with said spacewhereby air may be exhausted from the latter, substantially asdescribed.

11. In apparatus of the class described thecombination of a plurality ofsuperposed mold plates, means for sealing the space between the same toprevent the entrance of air to said space, a hollowconnectioncommunicating with said space, whereby air may be exhaustedfrom the latter, and a valve in said connection for opening or closingthe same, substantially as described.

12. In apparatus of the class described, the combination of a pluralityof superposed mold plates, one of said plates having a central moldingportion and an annularv -recess surroundlng said moldlng portion,

means for sealing the space between said plates to prevent the entranceof air to said space, and means communicating-with said recess wherebyair may be exhausted from the space between said plates, substantiallyas described.

13. In apparatus of the" class described, the combination of a pluralityof superposed mold plates each having a central molding portion and anannular. recess surrounding said molding portion and communicating withthe space between said molding portions, and means for sealing the spacebetween said plates to prevent the entrance 'of air to said last namedspace, one of said plates having means communicating with said recesseswhereby air may be' exhausted from the space between said plates,substantially as described.

14. As a new article of manufacture, a mold plate having an innermolding portion, a recess surrounding said molding portion, and a hollowconnection leading from said recess, substantially as described.

15. As a new article of manufacture, a

mold plate having an inner molding portion,

a recess surrounding said molding portion, a hollow connection leadingfrom said recess, and a valve for closing said connection, substantiallyas described.

16. In apparatus of the class described, the combination of a pluralityof superposed mold plates, one of said plates having a central openingtherein, means for sealing the space between said plates to prevent theen-` trance of air into said space, means for sealing said opening, andmeans whereby air may be exhausted from said space, substantially asdescribed.

This specification signed and witnessed this 11th day of October, 1912.

f. EDWARD L. AIKEN.

Witnesses:

FREDERICK BACHMANN, MARY J. LAIDLAW.

